The Sierra RS Cosworth was a high performance hatchback variant of the Ford Sierra that was introduced in 1986 and was built by Ford Europe. As Ford wanted to renew their sporting image in Europe, they decided to create a car capable of winning the Group A Touring Car championship. Ford decided on the Sierra as it was aerodynamic and the project would help raise the model's public profile. The project team reached out to Cosworth for an engine, who created the YB engines in order to power the RS Cosworth and its homologation version, the RS500 Cosworth. The YB engine was a 2.0L turbocharged inline four, which produced 204hp in base tuning, but was known to produce up to 600hp in highly tuned race versions. A total of 5,545 examples were created, with 500 of those being turned into the RS500. Ford would also later introduce a four door version known as the Sierra Sapphire RS Cosworth.